Lock with key activating alarm mechanism

ABSTRACT

A mechanical alarm in a door closure assembly whereby the insertion of a key into the outside lock will set in motion a device which will cause an audible signal.

United States Patent 559,631 5/1896 Sutton ..116 /80 Da Silva July 18, 1972 [54] LOCK WIT" ACTIVATING 689,322 12/1901 Plaster ..l 16/10 ALARM ISM 709,252 9/1902 Abbott ..l 16/ 10 2,047,861 7/1936 Downing ..l 16/92 [72] Inventor: Miguel Da Silva, 9] Old York Road,

Somerville, NJ. 08876 FOREIGN PATENTS OR APPLICATIONS [22] Filed: Nov. 2, 1970 2,963 1910 Great Britain ..116/80 [21] Appl' 85391 Primary Examiner-Louis J. Capozi [52] US. Cl. ..116/80, 70/441, 116/10 [57] ABSTRACT [51] Int. Cl. G081) 13/02 58 Field of Search ..116/8, 10, 12, 79, so 92- A mechamca' m a assembly whereby the 70/, 432 441 insertion of a key into the outside lock will set in motion a device which will cause an audible signal. [56] References Cited 1 i onwingn UNITED STATES PATENTS Patented July 18, 1972 INVENTOR Miguel do Silva BACKGROUND OF THE INVENTION Prior art directed at the safeguarding of doors from unauthorized entry leans heavily to the systems whereby the opening of the door will cause a circuit to be opened or closed to actuate an alarm.

The most serious drawback of these systems is that they usually are actuated by opening the door. This deprives the person being trespassed against to loose his first line of defence, the locked door. Also electric systems are expensive, create unsightly wiring and alarm units.

SUMMARY OF THE INVENTION It is therefore the primary object of this invention to provide a mechanical alarm system which is initiated by the insertion ofa key in the outside lock.

It is also an object of this invention to contain this alarm system within a door closure assembly.

DESCRIPTION OF THE DRAWINGS A better understanding of this invention may be obtained from the following drawings and description forming a part of this disclosure in which:

FIG. 1 is a cut away section view of the door closure and alarm assembly.

FIG. 2 is an enlarged view of the inside of the inner door knob taken along line 2-2 in FIG. 1.

FIG. 3 is a view taken along line 3-3 in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODYMENT A door is provided with a closure assembly 11 including an outside knob 12, an inside knob 13, a hollow knob spindle l4, bearing plates 15 and 16 and a lock assembly 17.

Closure assembly 11 also has the conventional latch and dead bolt which have no direct bearing on the working of this invention and are therefore not shown.

The knob spindle l4 coaxially surrounds a trip means such as a rod 18. The rod 18 is biased toward the outside knob 12 by a spring 19.

The spring 19 is contained toward the inner knob 13 by a washer 20 which slidably surrounds the rod 18 and engages the shoulder 21 formed by the two inside diameters of the spindle 14. The spring 19 is contained toward the outside knob 12 by a washer 22 which slidably surrounds the rod 18 and is held in place by suitable means such as a pin 23 pressed into the rod 18.

The end of the rod 18 which faces to the outside knob 12 extends into the lock assembly 17 by a predetermined distance.

A bell 24 is contained whthin and suitably attached to the inside of the knob 13.

A support member such as a bearing plate 27 is suitably attached to the inside of the inside knob 13.

The bearing plate 27 supports a pin 28 in rotatable engagement. The bearing plate 27 also supports a pin 29 in fixed engagement. A gear 30 is rigidly attached to the pin 28 and a second gear 31 engaging the gear 30 is rotatably fixed on the pin 29.

The pin 29 extends beyond the gear 31 and a flat coiled spring 32 has one of its remote ends suitably attached to the pin 29. As shown in FIG. 2 the other remote end of the spring 32 is suitably attached to the face of the gear 31.

As shown in FIG. 2 the plate 27 supports a third pin 33 in knob 13 to engage the shaped end of the pin 28.

holding means such as a pivoted pawl 37 is held in position by a pin 38. The pin 38 is held in rigid engagement by the walls of the inside knob 13.

The pivoted pawl 37 is rotatable around the pin 38 in an off center condition so that one end of the pawl 37, when not influenced by an outside force, is in constant engagement with the gear 31 and keeps the gear 31 from rotating about the pin 29. In operation a key 39 is inserted into the lock 17 in the outside knob 12. This pushes the rod 18 inward where it contacts the pivoted pawl 37 and causes the shaped end 41 of the pawl 37 to disengage from the gear 31.

The windup key 35 is inserted into the hole 36, and engaged on the pin 28.

The key 35 is turned and this motion is transmitted through the engagement of the gears 30 and 31 which winds the spring 32 in tension. When the proper tension on the spring 32 is reached the key 39 is withdrawn from the lock 40 and the spring 19 moves the rod 18 to the outside allowing the pawl 37 to pivot with the end 41 engaging the gear 31 to hold it rigid against the tension of the spring 32. The door 10 is then shut and the alarm is operable.

The insertion of any key such as 39 in the outside lock will move the rod 18, overcoming the bias of the spring 19, to engage the pawl 37. The pawl end 41 will disengage from the gear 31. This disengagement allows the gear 31 to be rotated rapidly by the release of the tension on the spring 32.

The rotation of the gear 31 will cause the end 42 of the bell beater 34 which rides on the teeth 43 of the gear 31 to occilate. This occilating movement will cause the hammer end 44 of the beater 34 to strike the bell body 24 and make an audible signal.

I claim:

1. A door lock comprising, in combination, an outside knob and an inside knob fitted on opposite ends of a hollow knob spindle extending through a door, a lock assembly within the interior of said outside knob and adjacent said end of said spindle, a trip rod extending through a center of said spindle and being spring biased toward said outside knob and into said lock assembly, a bell within said inside knob,.a bearing plate attached to the inner side of said inside knob, said bearing plate supporting a gear train attached to a spiral leaf spring, a hole through a wall of said inside knob for insertion of a key for winding up said gear train and spring which thus form a spring motor, a pawl within said inside handle being centrally pivotable about a stationary pin, one end of said pawl being aligned with one end of said trip rod and the other end of said pawl being aligned to fit between the teeth of a gear which forms a component of said gear train, a bell beater centrally pivotable about a stationary pin so that opposite ends thereof alternately strike said bell, the other end of said trip rod extending in said lock assembly being an alignment with an end of a key receivable into said lock assembly so to push said trip rod against said bias spring and pivot said pawl so to release said spring motor, and means whereby unwinding said motor causes back and forth oscillation of said bell beater to strike said bell to audibly warn that a key is inserted in said lock. 

1. A door lock comprising, in combination, an outside knob and an inside knob fitted on opposite ends of a hollow knob spindle extending through a door, a lock assembly within the interior of said outside knob and adjacent said end of said spindle, a trip rod extending through a center of said spindle and being spring biased toward said outside knob and into said lock assembly, a bell within said inside knob, a bearing plate attached to the inner side of said inside knob, said bearing plate supporting a gear train attached to a spiral leaf spring, a hole through a wall of said inside knob for insertion of a key for winding up said gear train and spring which thus form a spring motor, a pawl within said inside handle being centrally pivotable about a stationary pin, one end of said pawl being aligned with one end of said trip rod and the other end of said pawl being aligned to fit between the teeth of a gear which forms a component of said gear train, a bell beater centrally pivotable about a stationary pin so that opposite ends thereof alternately strike said bell, the other end of said trip rod extending in said lock assembly being an alignment with an end of a key receivable into said lock assembly so to push said trip rod against said bias spring and pivot said pawl so to release said spring motor, and means whereby unwinding said motor causes back and forth oscillation of said bell beater to strike said bell to audibly warn that a key is inserted in said lock. 